Undermattress

ABSTRACT

An undermattress consisting of a frame having a number of horizontal members and a supporting surface disposed thereon for a top mattress, said supporting surface being formed by a set of wire-shaped or tube-shaped elements parallel with one another which extend transversely over the horizontal members between the frame sides parallel therewith and which are secured against displacement in relation thereto.

[451 Oct. 1, 1974 2,909,216 l0/l959 Stern et al.

[ UNDERMATTRESS 3,188,073 6/1965 Schneider................ 3,441,961 5/1969 Johannes B. H. J. Rademaker, Winchoten [75] Inventor:

Poerink....,............. 5 194 x Netherlands [73] Assignee: B.V. Rawi Fabrieken v/hC.

Rademaker & Zoom, winsch t n, Primary Examiner.lames C. Mitchell Netherlands Attorney, Agent, or FirmSnyder, Brown and Ramik [22] Filed: Jan. 22, I973 121 Appl. No.: 325,447

ABSTRACT [30] Foreign Application Priority Data An undermattress consisting of a frame having a number of horizontal members and a supporting surface disposed thereon for a top mattress, said supporting surface being formed by a set of wire-shaped or tubeshaped elements parallel with one another which extend transversely over the horizontal members between the frame sides parallel therewith and which are secured against displacement in relation thereto.

References Cited UNITED STATES PATENTS 6 Claims, 3 Drawing Figures 2,803,293 Rowland..........,.........,........ 5/309 X 1 UNDERMATTRESS porting surface. To this end of course use is made for the supporting surface of a sheet of hardboard which.

is perforated to ensure satisfactory ventilation.

Although the result is a very rigid supporting surface, the accompanying ventilation is unsatisfactory. In the prior art mattresses which mainly use supporting surfaces made from steel wire the ventilation is very satisfactory, but the required rigidity is absent, no matter what added steps are taken.

It is an object of the invention to provide an undermattress which completely meets requirements and also results in a considerable saving of material in comparison with the prior art steel wire mattresses.

According to the invention, the supporting surface is formed by a set of wire-shaped or tube-shaped elements parallel with one another which extend transversely over the horizontal members between the frame sides parallel therewith and are secured against transverse displacement in relation thereto. A mattress support of this kind has a very large open surface, because the open spaces are bounded by two adjacent parallel elements and two horizontal members placed apart at a distance which is a multiple of the distance between the elements. The supporting surface is stiffened by the supporting effect of the horizontal members. The apertures cannot become imperrnissibly large, since the elements are secured against transverse displacement in relation to the horizontal members. A large amount of material is saved in comparison with the prior art steel wire mattresses, since use is made exclusively of straight wire-shaped or tube-shaped elements extending in one direction. This also has the advantage of reducing cost and making the mattress support very easy to handle.

According to one possible feature of the invention the elements are secured by their ends in the frame sides parallel with the horizontal members. In that case the elements need not be attached to the horizontal members in the longitudinal direction. According to another possible feature of the invention the horizontal members are secured in the long sides of the frame and the elements take the form of steel wires spot-welded to the horizontal members. The result is a very rigid construction, since the wires have only very short free portions and therefore local loading subjects only a small portion of the wire to tensile stressing.

Another special advantage is that the welding of the wire, first by its end to the first horizontal member and then successively to each following horizontal member, heats and therefore expands the wire, so that after cooling its free portions are prestressed.

According to a possible feature of the invention the horizontal members are formed with recesses in which the elements rest.

The result is that the elements are secured in a very simple manner against displacement in the transverse direction.

According to another possible feature of the invention the elements have a plastic coating by means of which they are glued or welded to the plastic coating of the horizontal members. In this way the elements can be secured in a very simple manner, and the mattress can be given an attractive appearance by the use of differently coloured plastics.

According to another possible feature of the invention the horizontal members have punched-out lips beneath which the elements are clamped. In that case there is no need for welding or glueing.

In a very advantageous possible embodiment of the mattress according to the invention, the horizontal members are formed by an angular section, more particularly a square tube, which is secured in a position such that the wire-shaped elements contact an angular edge of the section. A construction of this kind is very advantageous for spot-welding since it readily produces point contact between the wires and the horizontal members. There is also the advantage of obtaining the maximum free space between the wires.

An embodiment of the invention will now be described in greater detail with reference to the drawings, wherein:

FIG. 1 is a perspective view of a mattress according to the invention,

FIG. 2 is a section through a portion of the mattress illustrated in FIG. 1, taken parallel with its long side, and

FIG. 3 is a plan view of a portion of the mattress illustrated in FIG. I.

The mattress illustrated in the drawings consists of a frame of metal tube sections. Two sections 1, 2 form the long sides of the frame, while its short sides are formed by sections 3, 4 The frame can also be formed by wooden beams. The frame also has five horizontal members 5 secured, for instance by welding, to the long sides 1, 2. Sections 5 are formed by square tubes having one edge turned upwards. The mattress-supporting surface is formed by a set of straight wires 6 extending parallel at a short distance from one another along the long sides 1, 2 of the frame. The wires 6 are welded to the horizontal members 5. At their'ends the wires 6 are inserted into apertures in the sections 3 and 4 forming the short sides of the frame. The wires can be secured fairly tightly in the apertures by clamping. If the wires are welded to the horizontal members 5, there is no need for the wires to be rigidly secured in the short sides of the frame. However, this of course does not mean that in certain circumstances it may not be advantagous to secure the wires rigidly in the short sides of the frame by welding or in some other manner.

In the mattress support according to the invention the supporting surface is very rigid, since the wires 6 have a very short free length, so that they cannot stretch under loading. As a result they also have high resistance to sagging between the horizontal members 5.

What I claim is:

1. An undermattress consisting of a rigid frame of open rectangular construction and a plurality of rigid horizontal members extending between and joined to opposite sides of said frame in spaced relation to each other parallel with the ends of said frame whereby said open rectangular construction afforded by said frame is subdivided into a number of smaller open rectangular subframes, and a rigid mattress-supporting surface disposed within the open rectangular construction of said frame, said supporting surface being formed by a set of wire-shaped or tube-shaped elements disposed in spaced parallel coplanar relation with one another and parallel to said frame sides to extend transversely over the horizontal members between said frame ends, and means rigidly securing said elements to the assembly constituted by said frame and horizontal members for preventing displacement of said elements whereby to present a rigid mattress support which also provides a major portion of its area as ventilation openings.

2. An undermattress as set forth in claim 1, characterised in that the elements are secured by their ends in said frame ends.

. 3. An undermattress as set forth in claim 1 characterised in that said elements take the form of steel wires spot welded to said horizontal members.

4. An undermattress as set forth in claim 2 characterised in that said horizontal members are formed with recesses in which said elements rest.

5. An undermattress as set forth in claim 3 characterised in that said horizontal members are formed by an angular section more particularly a square tube, which is secured in a position such that said wire-shaped elements contact an angular edge of the section.

6. An undermattress as defined in claim 1 wherein said means comprises plastic coatings on said horizontal members and said elements, the plastic of said coatings being joined at points of contact between the elements and horizontal members. 

1. An undermattress consisting of a rigid frame of open rectangular construction and a plurality of rigid horizontal members extending between and joined to opposite sides of said frame in spaced relation to each other parallel with the ends of said frame whereby said open rectangular construction afforded by said frame is subdivided into a number of smaller open rectangular subframes, and a rigid mattress-supporting surface disposed within the open rectangular construction of said frame, said supporting surface being formed by a set of wire-shaped or tube-shaped elements disposed in spaced parallel coplanar relation with one another and parallel to said frame sides to extend transversely over the horizontal members between said frame ends, and means rigidly securing said elemEnts to the assembly constituted by said frame and horizontal members for preventing displacement of said elements whereby to present a rigid mattress support which also provides a major portion of its area as ventilation openings.
 2. An undermattress as set forth in claim 1, characterised in that the elements are secured by their ends in said frame ends.
 3. An undermattress as set forth in claim 1 characterised in that said elements take the form of steel wires spot welded to said horizontal members.
 4. An undermattress as set forth in claim 2 characterised in that said horizontal members are formed with recesses in which said elements rest.
 5. An undermattress as set forth in claim 3 characterised in that said horizontal members are formed by an angular section more particularly a square tube, which is secured in a position such that said wire-shaped elements contact an angular edge of the section.
 6. An undermattress as defined in claim 1 wherein said means comprises plastic coatings on said horizontal members and said elements, the plastic of said coatings being joined at points of contact between the elements and horizontal members. 